This invention relates generally to the removal of halogens from halogenated hydrocarbons. Chloride compounds and other halogens cause numerous problems when associated with hydrocarbons used in various applications.
Chloride compounds have been recognized for some time as serious poisons to many catalytic reactions. Chlorides are extremely corrosive to processing equipment. Hydrocarbons products frequently contain small amounts of chlorine in the form of chemically combined chlorine. There are many ways in which small amounts of chemically combined chlorine can be introduced into a hydrocarbon product during the production or treatment thereof. Usually, however, chemically combined chlorine becomes a part of the hydrocarbon product during the reactions in which the hydrocarbons product is produced, because many chloride catalysts often introduce chlorine into the product which is not removable by water or caustic wash.
If chemically combined chlorine is not removed from hydrocarbon products, such as gasoline or other fuels, corrosion of engine parts can result, and the presence of chemically combined chlorine may also diminish the effect of tetraethyl lead or other additives when hydrocarbons products are used as fuels for internal combustion engines. Similarly, chemically combined chlorine in a solvent, such as an electrostatic toner solution, can cause interference in the end use of the solvent. Propane gas burned in homes has at times contained so much fluorine that when burned hydrogen fluoride was formed, severely etching the windows in the homes.
Additionally, there has been a recent increase in the use of shale oil. Raw retorted shale oil is unsuited for use as a refinery feedstock or as a finished fuel product because it contains excessive quantities of nitrogenous, compounds such as amines, amides, nitriles, pyrroles, indoles and carbazoles. One method for reducing these nitrogenous species in shale oil has been by hydrogenation of the weakly basic nitrogen compounds into stronger bases followed by anhydrous hydrogen chloride treatment to separate a non-miscible amine hydrochloride adduct. This treatment, however, leaves the resultant hydrocarbon stream contaminated with undesirable chloride ions.
For application to the above situations and others where halogen contamination of a hydrocarbon stream causes difficulties, it is necessary to have an inexpensive and efficient method for the removal of halogen ions from the hydrocarbon stream.
The present invention discloses a method by which chlorine and other halogens can be removed from the hydrocarbon product.